13130
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 8
- Digital Root
- 8
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 16
- Divisor Sum
- 25704
- Proper Divisor Sum (Aliquot Sum)
- 12574
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 4800
- Möbius Function
- 1
- Radical
- 13130
- Omega Function (Ω)
- 4
- Little Omega Function (ω)
- 4
Special
- Factorial
- no
- Catalan Number
- no
- Bell Number
- no
- Motzkin Number
- no
- Primorial
- no
Figurate Numbers
- Fibonacci Number
- no
- Triangular Number
- no
- Perfect Square
- no
- Perfect Cube
- no
- Pentagonal Number
- no
- Hexagonal Number
- no
- Lucas Number
- no
- Tetrahedral Number
- no
- Pell Number
- no
- Tribonacci Number
- no
- Pronic Number
- no
Recreational
- Happy Number
- no
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 76
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- no
- Squarefree Number
- yes
- Prime Power
- no
- Prime Factorization
- no
- Twin Prime
- no
- Mersenne Prime
- no
- Sophie Germain Prime
- no
- Safe Prime
- no
- Powerful Number
- no
- Achilles Number
- no
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- yes
- Odd
- no
Appears in sequences
- Sum of 10 nonzero 8th powers.at n=21A003388
- Numbers k such that 10*3^k - 1 is prime.at n=41A005542
- Positive numbers k such that k and 2*k are anagrams in base 5 (written in base 5).at n=9A023061
- Length of hypotenuse squared in right triangle formed by a prime spiral plotted in Cartesian coordinates.at n=22A048851
- Number of distinct differences between consecutive divisors (ordered by increasing magnitude) of n! which are not also divisors of n!.at n=21A060738
- a(n) = prime(n+1)^2 + prime(n)^2.at n=21A069484
- Take the list t(n,0) = {1,...,n}; denote by t(n,j) this list after rotating to left (or right) by j positions. Calculate inner product of t(n,0) and t(n,j) and denote the value by s(n,j). Compute this inner product for all j = 1..n and choose the smallest. This is a(n).at n=38A088003
- Let [n] = {1,2,...,n}. Let G_n be the union of all closed line segments joining any two elements of [n] X [n] along a vertical or horizontal line, or along a line with slope +-1. Then a(n) = combined total of the number of (nondegenerate) triangles and rectangles for which all edges are subsets of G_n.at n=10A098921
- Sums of antidiagonals of A099239.at n=10A099241
- Number of permutations avoiding 3142, 25314, 246135 and 362514.at n=7A120346
- Numbers n such that 6n and 12n are both the average of twin prime pairs.at n=24A177680
- Let f(n) = Sum_{j>=1} j^n/binomial(2*j,j) = r_n*Pi*sqrt(3)/3^{t_n} + s_n/3; sequence gives r_n.at n=6A181334
- a(n)=a(n-1)+a(n-2)+n+4, a(0)=0, a(1)=1.at n=16A210675
- Numbers that can be represented as a sum of two distinct nontrivial prime powers in three or more ways.at n=12A225104
- Numbers whose arithmetic derivatives are a permutation of their digits.at n=23A225902
- Numbers which are the sum of two squared primes in exactly four ways (ignoring order).at n=4A226599
- Expansion of phi(x) / phi(x^2) * f(-x, -x^7) / f(-x^3, -x^5) in powers of x where phi(), f() are Ramanujan theta functions.at n=36A230534
- Numbers k that are the product of four distinct primes such that x^2+y^2 = k has integer solutions.at n=18A248712
- Number of (n+2) X (3+2) 0..3 arrays with every consecutive three elements in every row and diagonal having exactly two distinct values, and in every column and antidiagonal not having exactly two distinct values, and new values 0 upwards introduced in row major order.at n=17A252714
- Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 206", based on the 5-celled von Neumann neighborhood.at n=34A270735